This invention pertains to the construction of an indoor unit for an electric heat pump of a size and character typically usable for residential conditioning.
As is the case in connection with U.S. patent application Ser. No. 461,796, filed Jan. 28, 1983 relating to an outdoor unit for an electric heat pump, the construction arrangement of this invention arose from a project to provide a companion indoor unit for an electric heat pump particularly adapted for use in northern climates, and one in which attention is particularly paid to obtaining higher efficiencies in the heating mode of the unit. As there noted, one way in which to improve heating efficiencies is to locate the refrigerant compressor indoors.
The major components of a refrigerant circuit which can be located indoors for a heat pump are the compressor with external muffler, the indoor heat exchanger with a coil partitioning solenoid valve is used, the expansion and reversing valves, the suction line accumulator and the filter dryer. Also required for an indoor unit are the air mover, the supplementary resistance heat package normally provided for a northern climate heat pump, and the control system plus the electrical components associated with the heat package. Further, to obtain high efficiency operation for the indoor unit as a whole, the air mover contemplated is a centrifugal blower with backward inclined blades equipped with a special inlet and outlet arrangement, as distinguished from the typical forward curved vane centrifugal fan. Such a blower takes more space than the conventional squirrel cage blower.
Accordingly, it is the aim of the invention to achieve an optimum arrangement or packaging of these components in an indoor unit. Such an optimum packaging might best be defined as that arrangement which most completely satisfies, to the best of our knowledge, the combined requirements of excellent thermal-mechanical performance, economic manufactureability, easy maintainability and good marketability. The arrangement should also be such as to provide flexibility of mode of installation since there exists a wide variety of locations within the typical dwelling where the unit might be sited.
The indoor unit of this invention is considered to satisfy such requirements.